I 



A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE 



" To the solid ground 

 Of Nature trusts the mind ivhich builds for aye." — WORDSWORTH 



No. 472, Vol. 19] 



THURSDAY, NOVEMBER 14, 1878 



[Price Sixpe>xe 



Registered as a Newspaper at the General Post Office.] 



[.\11 Rights are Reserved. 



BEOWNING'S INDUCTION COILS. 



MR. JOHN BROWXIXG begs to inform scientific gentlemen that the adoption of an improved method of 



winding Induction Coils has enabled him to increase their efficiency 

 guaranteed to give the length of spark named. 



Induction Coil, to give a \ in. spark in dry air 



Induction Coil, to give a I in. spark ..'. 



Induction CoiJ, to give a li in. spark 



Induction Coil, to give a ih in. spark 



Induction Coil, to give a 3i in. spark 



Induction Coil, to give a 4i in. spark 



Induction Coil, to give a 6 in. spark 



and reduce their cost. Every Coil is 



LIST OF ELECTRIC LAMPS AND LANTERNS SENT FREE. 



JOHN BROWNING, 



OPTICAL AND PHYSICAL INSTRUMENT MAKER TO H.M. GOVERNMENT, THE ROYAL SOCIETY, THE 

 ROYAL OBSERVATORIES OF GREENWICH AND EDINBURGH, AND THE OBSERVATORIES OF 

 KEW, CAMBRIDGE, DURHAM, UTRECHT, MELBOURNE, &c., &c. 



63, STRAND, W.C. 



FACTORY-SOUTHAMPTON -STREET, LONDON, W.C. 



